if i were to guess: the locks aren't locks but prevent the window from openening too far. They should move pretty free up and down, and by pushing the window out, they move upward.

Can you remove the screen to get a better view? In my experience, windows sometimes get stuck. especially if You have some foam insulation on it. Usually all it requires is some percussive maintenance: remove screen, turn the crank up to where it meets resistance, then just whack the window frame with the palm of your hand on the bottem, see if it comes loose. Don't use tools or hit too hard. Glass can break. Oh, also check the outside. Maybe someone screwed it to the frame?